Various instruments are known in the prior art for end-to-end and end-to-side anastomotic surgical stapling together of parts of the alimentary canal (i.e., esophagus, stomach, colon, etc.). These instruments employ staple cartridges, generally in the shape of a hollow cylinder, of different sizes to accommodate tubular organs of varying diameters. End-to-end and end-to-side anastomoses are achieved by means of at least one ring of surgical staples.
The traditional technique for surgical stapling anastomosis is to position the stapling cartridge within the tubular organ to be stapled. The cut end of the tubular organ is inverted (i.e., folded inwardly) over the annular end of the staple cartridge creating an inverting anastomosis upon stapling. An essential requirement of the inverting anastomotic technique is the incorporation of knives within the staple cartridge housing to trim excess tissue from the anastomotic connection.
The prior art anastomotic stapling instruments form generally circular anastomotic connections, and have been largely limited to alimentary organs. With respect to end-to-side vascular anastomosis, circular connections, rather than an elliptical connections, are sometimes disadvantageous as they are less physiologic or natural. This unnatural connection may create turbulence in the blood flow as it courses through the anastomosis, damaging the intima (i.e. inner wall) of the blood vessel and predisposing it to forming blood clots.
In the present state of the art end-to-end and end-to-side anastomosis between blood vessels have typically been accomplished by hand-sewn suturing techniques. These techniques are time consuming, not as reliable as stapling, and subject to greater human error than stapling. Current stapling instruments used for alimentary canal are not suitable, however, for vascular anastomosis due to their large sizes and inability to provide non-circular and low turbulence anastomoses. A typical prior art instrument has a circumference of approximately 8 cm (3 in), far too thick to accommodate coronary arteries and veins, which have circumferences ranging from 0.50 to 1.0 cm and from 1.5 to 2.5 cm, respectively.
An additional drawback of prior stapling instruments is the inability to provide an everted (i.e., folded outwardly) anastomosis. An inverted vascular anastomosis would expose the cut ends of the blood vessels to the vessel lumen and could lead to the formation of blood clots. For this reason, hand-sewn everted anastomoses for vascular connections are preferable, despite time and reliability drawbacks.
Accordingly, it is a general object of the present invention to provide an improved instrument and method for vascular anastomosis.
It is also an object of the present invention to provide a surgical stapling instrument small enough to accommodate vascular lumens.
Another object of the present invention is to provide a surgical stapling instrument for everted anastomosis.
Another object of the present invention is to provide a method for surgical stapling that does not require the removal of excess tissue from the anastomotical connection.
Still another object of the present invention is to provide an instrument and method for vascular anastomosis that is less time-consuming and more reliable than the prior art.